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As interest in hydrogen energy grows, eco-friendly methods of producing hydrogen are being explored. CuBi2O4 is one of the p-type semiconductor cathode materials that can be used for photoelectrochemical hydrogen production via environment-friendly water electrolysis. CuBi2O4 has a bandgap of 1.5 – 1.8 eV which allows it to photogenerate electrons and holes from the absorption of visible light. This study investigated the effect of sulfur doping on the bandgap and photoelectrochemical water reduction properties of CuBi2O4. Sulfur-doped CuBi2O4 thin films were electrochemically synthesized using a nitrate-based precursor solution with thiourea. This was followed by two-step annealing in an Ar atmosphere, which effectively prevented the oxidation of sulfur. Sulfur doping up to 0.1 at% led to the expansion of the lattice volume of the CuBi2O4. The bandgap was reduced from 1.9 eV to 1.5 eV with increasing doping concentration, which resulted in the enhancement of photoelectrochemical current density by ~240%. X-ray photoelectron spectroscopy showed that sulfur-doping reduced oxygen vacancies with increasing doping concentration, confirming that the enhanced photoelectrochemical properties resulted from the reduction in bandgap, not from any extrinsic factor such as oxygen vacancies. Further studies of sulfur-doped CuBi2O4 to improve surface coverage are expected to lead to a more promising photoelectrochemical cathode material.

In a wireless sensor network, data flows in two main directions. There are flooding that transfers data from the sink node to the entire node and routing that transfers data sensed by each sensor node to the sink node. Transferring data from the sink node of the wireless sensor network to the entire sensor node is called flooding. In an energy-constrained environment, a more efficient method has been developed, because the most basic flooding technique contains a lot of data redundancy. In this paper, the combination of the distance-based approach and the neighboring node information method is proposed as a more energy-efficient method. Flood data can be transmitted by adjusting the angle of the transmission line within the transmission radius to the shape of a fan and limiting the distance within the communication radius. The redundancy and connectivity of data were compared and examined according to angle and distance values, and the experiment proved that the proposed method can provide connectivity to the entire sensor node while reducing data redundancy. It was confirmed that the optimal angle and distance could change according to the density and communication radius of the network. Additional research will be needed, such as a method that can dynamically calculate the optimal angle and distance while taking into account factors like network density and communication radius.

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In a wireless sensor networks, many topics have been studied in several filed. Most of them are concentrated on efficient use of energy to prolong the network lifetime. In a special environment like as remote battlefield, desert, forest, it is more difficult to recharging the battery of sensor. In this paper, we propose a density control method in a dense wireless sensor. We prolong the lifetime of network by selecting small set of active sensor nodes. Hopbased disjoint wakeup method is used and calculates the hop count with adjustment of communication radius. We analyzed the number of active sensor node and compared with other method with simulation.

GITR (glucocorticoid-induced TNF receptor) is a recently identified member of the TNF receptor superfamily. The receptor is preferentially expressed on CD4(+)CD25(+) regulatory T cells and GITR signals break the suppressive activity of the subset. In this study, we wanted to reveal the in vivo function of GITR in herpes simplex virus type 1 (HSV-1) infection. A single injection of anti-GITR mAb (DTA-1) immediately after viral infection significantly increased the number of CD4(+) and CD8(+) T cells expressing CD25, an activation surface marker, and secreting IFN-gamma. We confirmed these in vivo observations by showing ex vivo that re-stimulation of CD4(+) or CD8(+) T cells with a CD4(+) or CD8(+) T-cell-specific HSV-1 peptide, respectively, induced a significant elevation in cell proliferation and in IFN-gamma secretion. Our results indicate that GITR signals play a critical role in the T-cell immunity to HSV-1.